Morbidity and resource usage after myectomy- or pacing-treatment in hypertrophic obstructive cardiomyopathy: A case-control study

Background: Treatment of left ventricular outflow-obstruction (LVOTO) in hypertrophic obstructive cardiomyopathy (HOCM) by short atrio-ventricular delay pacing has long-term hemodynamic results that are not inferior to myectomy, but publications comparing long-term morbidity following those treatments are lacking. Methods: A search for HOCM-patients attending all ten hospitals in the West Gotaland Region, Sweden, from 2002 through 2013, identified 251 patients (42 treated with myectomy, 88 with pacing and 121 conservatively). As the age at procedure was significantly lower in the myectomy-group compared to the pacing-group, morbidity was compared by case-control methodology, matching patients for age, maximal wall thickness and LVOT-gradient. We found 31 pairs who constituted the comparison-groups. Post-intervention median follow-up was 15.4 and 10.4 years in pacing- and myectomy-group, respectively. Post-procedural and long-term complications and re-interventions, length of stay, and cost of hospitalization were documented. Results: Both treatments improved New York Heart Association class and LVOT-gradients significantly. There were fewer peri-procedural complications in the pacing-group compared to myectomy-group (3.2% and 35.5% p < 0.001). During follow-up pacemaker was implanted in 35.5% of myectomy-group for atrio-ventricular block, 9.7% peri-operatively, and 25.8% during late-follow-up. Furthermore, the pacing group had a superior freedom from all re-interventions, 90.3% versus 61.3% in myectomy-group (p = 0.003). Pacing patients had a shorter in-hospital stay (median 4 [IQR = 2] days) compared to myectomy 11 [7] days; P < 0.001). The mean cost of hospitalization was 74,000 +/- 16,000 SEK for pacing and 310,000 +/- 180,000 SEK for myectomy, p < 0.001. Conclusion: Pacing is a simple and reliable treatment for drug-refractory HOCM-patients with low rate of complications and costs. (C) 2020 Elsevier B.V. All rights reserved.